Recovery of Delayed Coker Propylene At Turndown...Recovery of Delayed Coker Propylene At Turndown...
Transcript of Recovery of Delayed Coker Propylene At Turndown...Recovery of Delayed Coker Propylene At Turndown...
Saudi Aramco TOTAL Refining & Petrochemical Company (SATORP)
Presenter: Hamoud Al QahtanProcess Engineer, SATORP
Recovery of Delayed Coker Propylene
At Turndown
Outline:
•Satorp
•Delayed Coker Configuration & Basis of Design
•Re-Processing of Off-Spec LPG
•Observed Propylene Loss
• Analysis and Troubleshooting
• Recommendations
• Actions and Results
• Q & A
Re-Processing of Refinery Off-Spec LPG
• Through Merox Unit
• Through DCU ( through HP receiver and Debut.
Observed Propylene Lost
1- Occasional Loss of Propylene Recovery
2- Propylene lost when off –Spec LPG is re-processed
3- Evaluation of Main Stripper Operation
Yellow: opening of off spec LPG valve to HP drum
Blue: propylene mole fraction in LPG
Green: propylene Mole fraction in FG
Light Orange: LPG Flow to R/D
Dark Blue: opening of off spec LPG valve to HP drum
Light Blue: Temperature of HP drum vapor
Purple: Temperature of HP drum liquid
Analysis and Troubleshooting
Simulation of the drum at:
Different quality of Off-Spec LPG:• Low Propylene content• High propylene content• Pure propylene
Different flows, 0 , 5 and 10 T/H
Different pressure:• Actual Pressure , 12.5 barg• H&M balance pressure 13.8 barg
Observed Propylene Lost
1- Occasional Loss of Propylene Recovery
2- Propylene lost when off –Spec LPG is re-processed
3- Evaluation of Main Stripper Operation
Main Stripper Operation
Bottom temperature relatively high
a- Undetectable C2 in Coker LPG (design 0.5 wt% max)
b- H2S in sour LPG is less than 0.1 wt%( design 6 – 7 wt%)
Actions and Results
• Gas plant pressure slightly increased
• Stripper bottom temperature reduced from 158 0C to 154 degC
• High Recovery achieved and propylene produced increased 250 %